Dr. Dizon on PTEN Mutations in Endometrial Cancer

Don S. Dizon, MD, Assistant in Medicine, Medical Gynecologic Oncology, Massachusetts General Hospital, explains the relationship between PTEN mutations and mTOR inhibitors in endometrial cancer.

PTEN mutations most commonly mark type I endometrial cancer. In addition to PTEN mutations, endometrial cancer also activates the mTOR and PI3K/AKT pathways. Dizon says that the evaluations with mTOR inhibitors, which can block PTEN, have been mixed. Trials involving the mTOR inhibitors temsirolimus, deferolimus, and everolimus suggest that the treatments can be used in patients who have been less pretreated. In a National Cancer Institute of Canada study, the response rate for patients with no prior chemotherapy fell from 25% to 9% when patients did have prior chemotherapy, Dizon says.

Dizon says that there is a need to identify a population based on the PTEN mutation that would benefit from treatment. The end goal would be to conduct an enriched study in that population.